Development of a Sampling Patch to Measure Dermal Exposures to Monomeric and Polymeric 1,6-Hexamethylene Diisocyanate: A Pilot Study

Abstract

The purpose of this study was to develop and evaluate a patch sampler to monitor dermal exposures to monomeric and polymeric 1,6-hexamethylene diisocyanate (HDI) in the automotive refinishing industry. Different patch materials were used to construct the patches, and patches impregnated with a derivatizing solution were compared with those that were not impregnated. We observed that impregnated felt patches measured significantly more HDI monomer (p = 0.04) than non-impregnated patches in a controlled experiment. Both impregnated and non-impregnated patches were compared with the tape-strip method by monitoring three spray painters’ dermal exposure to monomeric and polymeric HDI. Isocyanurate was the predominant species measured by all three sampler types with detectable levels in >86% of samples. Overall, tape-strips of exposed skin measured lower levels of monomeric and polymeric HDI than impregnated patch samplers at the same sampling site on the skin. Unlike tape-strips, impregnated patches are not as prone to evaporative or reactive losses or losses due to rapid penetration into the skin. Further investigations are warranted to evaluate these and other methods to measure dermal exposure to workers under occupational conditions to better understand the relationship between dermal exposure and internal dose.

Keywords:

• 1,6-hexamethylene diisocyanate (HDI)
• dermal exposure
• dermal sampling
• polyisocyanate
• sampling method

Acknowledgments

This research was approved by the Institutional Review Board in the Office of Human Research Ethics at the University of North Carolina at Chapel Hill and supported by National Institute for Occupational Safety and Health (T42 OH008673). The authors are grateful to Dr. Sheila Flack for her assistance with field sampling.

Notes

^A Sample amount/reference amount × 100.

^A Percentage measured by five consecutive tape-strips compared with the respective patch sampler provided in parentheses.

^B Summation of five consecutive tape-strips.